The Affordable Care Act has taken center stage as congressional Republicans scurry to dismantle it, nearly seven years after its passage. During that time, the landmark health reform law has greatly altered the health care landscape in Maine and across the country, in ways both obvious and obscure.

Whether you’re rooting for its repeal, praying for its survival, or you fall somewhere in between, it’s a good time to review the Affordable Care Act’s impact in Maine. Let’s look at three of the most talked-about aspects of the law: Healthcare.gov, protections for consumers and Medicaid.

Healthcare.gov

First things first: the Affordable Care Act is not universal health care. That’s a system most other industrialized nations use in which the government, rather than private insurers, pays the health care costs for its citizens. The Affordable Care Act is built on the existing health insurance system, with many people covered through government programs such as Medicare and Medicaid and most others through their jobs.

The health insurance marketplace you’ve heard so much about — think Healthcare.gov — targets another, smaller group: people who buy their own health insurance. Known as the “individual market,” this includes the self-employed, early retirees and low-wage workers. Healthcare.gov allows them to compare and shop for plans sold by private health insurance companies.

In Maine, that group includes about 77,000 people who plan to buy a policy through Healthcare.gov in 2017. (That’s no small number, but to put it in perspective, 10 times more Mainers get their insurance through work.) Small businesses, to a lesser extent, also use Healthcare.gov to provide health insurance to their workers.

Most of these consumers are eligible for financial assistance from the government to help them pay their premiums and out-of-pocket medical costs.

If the Affordable Care Act is repealed without a replacement, these 77,000 people would likely lose their coverage. Among them are nearly 20,000 Mainers with mental illness or substance use disorders who would lose access to counseling and addiction treatment, according to a new study by Harvard Medical School and New York University.

Many of these people can’t afford to buy coverage on their own without the government subsidies, and because Maine didn’t expand Medicaid under the Affordable Care Act, they may not qualify for that program either. Without any insurance, they may put off needed medical care or wind up in the emergency room, leaving hospitals to foot the bill.

Consumer protections

Even if you don’t buy coverage through Healthcare.gov, the Affordable Care Act still affects you. The law ushered in a number of requirements aimed at preventing insurance companies from taking advantage of consumers:

— Young adults up to age 26 can remain on their parents’ health plan.

— Insurers may no longer deny coverage to people with pre-existing health conditions, or charge them more.

— Prohibits insurers from applying lifetime monetary caps on insurance coverage and limits the use of yearly caps.

There’s speculation that some of these protections, popular with consumers, could survive a repeal of the Affordable Care Act. Even if they’re quashed at the federal level, Maine actually imposed some of them before the Affordable Care Act came along. State legislators could decide to keep those longstanding protections in place.

Take pre-existing conditions, for example, which an estimated 230,000 Mainers have. Maine law prevents insurers from denying coverage or charging more to customers with such conditions, but it gives them a year to say no.

But Maine’s demographics could make the state vulnerable in other ways.

The Affordable Care Act includes a number of provisions that prevent premiums from varying too widely among individuals. One of them allows insurers to charge older, sicker enrollees no more than three times as much as a lower risk, younger person. Some of the Republican plans for replacing the Affordable Care Act propose widening that spread to, say, five times. In a relatively old state such as Maine, that could mean much higher premiums for many residents, though lower monthly costs for younger ones.

As a rural state, Maine also could be disproportionately affected if Republicans move to loosen regulations over health provider networks. Under the Affordable Care Act, President Barack Obama’s administration required insurers to have a certain number of doctors, hospitals and other health providers in each area where the companies sell health plans. Enforcement of those requirements could ease up or disappear, some predict, meaning that even if consumers have coverage, they might not be able to find a doctor close by.

Medicaid

The Medicaid program, which provides health insurance for low-income Americans, is jointly run by the states and the federal government. The feds pay for about 60 percent of the costs, and in turn require states to cover certain groups of people and provide specific benefits. Anyone who meets the eligibility requirements (which vary by state) is guaranteed coverage. The federal government’s commitment to pay is open ended.

Republicans have proposed shifting Medicaid to a block grant, in which the feds would award states with annual lump sums. States could then run their programs as they see fit, but they’d also have to foot the bill for costs that exceed the federal allotment.

“It’s a way for the federal government to budget Medicaid going forward, and the states then have the financial risk of the fluctuations and swings in their economy,” said Andrew Coburn, a rural health expert at the Muskie School of Public Service at the University of Southern Maine.

Gov. Paul LePage has already seen fit to tighten eligibility requirements for Medicaid, known as MaineCare, and would have greater freedom to do so under a block grant approach. The program covers more than 273,000 people in Maine.

Many details of this proposal remain to be ironed out, including how the federal allotments would be calculated and whether overall Medicaid funding would be cut.

Another question mark is whether an effort to expand MaineCare, as the Affordable Care Act envisioned, might finally take hold in Maine. Proponents say they’ve collected enough signatures to put the measure on the 2017 ballot. Legislative efforts to expand MaineCare have failed six times, facing opposition from LePage and most legislative Republicans, who argue it would ruin the state budget.

Those are just the broad strokes on how repeal of the Affordable Care Act could affect health insurance in Maine. Even if the law ultimately dies, consumers who gained coverage under it are unlikely to lose that insurance until at least next year.

And health insurance is only the most visible part of the law, which also includes a range of lesser-known provisions, from requiring employers to provide women with a place to breastfeed to helping rural hospitals get discounted medications.

For now, patients, insurers and the health care industry are left to wait and wonder about the future of the Affordable Care Act, and what may — or may not — take its place.